Most people have battle cries. Not so much for Legolas. Legolas had what you're typical everyday person would call a battle song/sing-a-long. Which actually worked better than if he had had a battle cry because his battle song/sing-a-long (beautiful though it was) was extremely long and way too drawn out for anyone's own good (except perhaps for Legolas).
Five minutes in to his battle song/sing-a-long.
Legolas: Everybody clap your hands! (Clap clap clap clap clap clap clap clap…)
Aragorn (The only one not yet knocked out because he had a pair of pink earmuffs for the occasion) WILL YOU SHUT UP ALREADY!
Legolas: I most certainly shall not! Hey everybody! Let's start jumping-
At that moment, Aragorn suddenly whacked Legolas on the head and the youthful looking but actually extremely old elf was conked out for quite some time. Aragorn woke everyone but the orcs and Legolas.
Frodo: What just happened? My head is all tingly feeling.
Pippin: Was Leggy doing that weird cheerleader thing again?
Merry: You mean that song/sing-a-long thing he does?
Pippin: I am sooo in the mood to change my name to Pimpin. Isn't that keen!
All: No.
Even the unconscious Legolas mutters "no" in his unconsciousness.
Pimpin- I mean Pippin: Well I won't answer to anything but Pimpin! So there!
Everyone but Pippin looks to the sky as a ray of light falls through the clouds and "Halleluiah!" plays in the background.Gimli: Somebody help me put elf-boy in his straitjacket.
Sam: I will bride-girlfriend! Ahem! I mean, sure.
